HIV neuropathogenesis related to exosomes containing HIV non-coding RNAs

 描述(由申请人提供)：尽管血液中有足够的购物车和出色的病毒学控制，但近三分之一的艾滋病毒感染者仍会出现神经认知缺陷。这种神经认知缺陷统称为HIV-1相关性神经认知障碍(HAND)。在感染的后期，当出现全身免疫衰竭时，病毒也可能再次进入大脑。病毒的复制能力取决于细胞类型及其激活状态。一旦进入脑实质，它就存在于血管周围的巨噬细胞和小胶质细胞中，这些细胞为艾滋病毒提供了高效复制和进化的场所。最近的研究表明，在有大量巨噬细胞聚集的脑膜中也有大量的病毒负载。在这些区域内，艾滋病毒感染巨噬细胞/小胶质细胞和星形胶质细胞，这些细胞通常位于构成血脑屏障的血管周围区域。血管周围和脑膜巨噬细胞已被证明是病毒在人脑中活跃复制的部位。Exosome是由多种细胞产生的膜结合的囊泡，含有经典的膜标记蛋白，如四氢青霉毒素、黏附蛋白和金属蛋白酶。它们被认为通过靶细胞摄取或通过膜受体诱导细胞信号在细胞间通讯中发挥重要作用。除了膜蛋白，外切体还携带mRNAs和非编码RNAs，包括被认为影响靶细胞基因调控的miRNAs。我们团队和其他人的研究表明，感染HIV-1的细胞产生外体，通过一种名为TAR的dsRNA激活幼稚的靶细胞。我们的长期目标是了解来自HIV-1感染细胞的外切体在调节宿主-病毒相互作用中所起的作用。我们推测，感染细胞外体中存在的独特的病毒RNA将改变受体细胞，影响基因表达的调节和炎症反应的建立。我们的目标包括：鉴定CART下受感染的供体细胞的外切体的生物发生和功能(目标I)；鉴定经抑制剂处理的受感染细胞的外切体及其细胞来源(AIM II)，并明确TAR对受体细胞中TLR调节和细胞因子产生的影响的机制。总体而言，我们的数据表明，CART下的感染细胞仍然分泌焦油相关的外切酶，这些外切体激活幼稚的受体细胞，导致不需要的促炎信号。这些活性将被使用抑制剂逆转，并在体外血脑屏障模型和人源化HIV感染潜伏模型中进行测试。

 DESCRIPTION (provided by applicant): Nearly one third of HIV-infected individuals develop neurocognitive deficits despite adequate cART and excellent virological control in the blood. This range of neurocognitive deficits is collectively referred to as HIV-1-associated neurocognitive disorders (HAND). Virus may also enter the brain again in the later stages of infection when there is a general immune failure. The ability of the virus to replicate depends on the cell type and its state of activation. Once inside the brain parenchyma, it resides in perivascular macrophages and microglial cells that provide the site of productive replication and evolution for HIV. Recent studies suggest that there is a substantial viral load in the meninges as well where there is a rich collection of macrophages. Within these regions, HIV infects the macrophages/microglia and astrocytes most commonly located in the perivascular regions where they constitute the blood-brain barrier. Perivascular and meningeal macrophages have been shown to be sites of active viral replication in the human brain. Exosomes are membrane-bound vesicles produced by a variety of cells that contain classical membrane marker proteins such as tetraspanins, adhesion proteins and metalloproteinases. They are considered to play an important role in intercellular communication either by target cell uptake or by inducing cell signaling via membrane receptors. In addition to membrane proteins, exosomes carry mRNAs as well as non-coding RNAs, including miRNAs that are thought to affect gene regulation in the target cells. Research by our group and others has shown that HIV-1-infected cells produce exosomes that activate naïve target cells through a dsRNA called TAR. Our long term goal is to understand the role played by exosomes originating from HIV-1 infected cells in regulating host-virus interactions. We hypothesize that unique viral RNA present in the exosomes of infected cells will alter recipient cells impacting regulation of gene expression and establishment of inflammatory response. Our aims include: To characterize the biogenesis and function of exosomes from infected donor cells under cART (Aim I); To characterize exosomes from infected cells treated with inhibitors and their cellular origin (Aim II), and defining the mechanim of TAR effect on TLR modulation and cytokine production in recipient cells. Collectively our data indicates that infected cells under cART still secrete TAR associated exosmes and that these exosomes activate the naïve recipient cells resulting in unwanted proinflammatory signals. These activities will be reversed with use of inhibitors and tested in both an in vitro BBB model and humanized latent model of HIV infection.